1. Field of the Invention
The present invention relates to an image forming apparatus including a detection unit detecting information concerning a recording material on which an image is formed, and relates to an image forming method thereof. More specifically, the present invention relates to an image forming apparatus, such as an ink jet printer, a copier, and a laser printer, which controls image forming conditions based on a result of detection performed by a detection unit detecting information concerning properties or a type of the recording material and perform an image forming operation according to the properties or the type of the recording material, and relates to an image forming method thereof.
2. Description of the Related Art
Image forming apparatuses which form an image based on an image signal are of various types such as an electrophotographic type and an ink jet type. In such an image forming apparatus, printing paper (recording materials) as printed media is varied, and there are media provided with various characteristics including size, transparency, gloss, and the like. Under the circumstances mentioned above, in order to obtain high image quality, it is necessary to perform image formation optimal to such a variety of media.
Generally, laser printers which are of the electrophotographic type are widely used as image forming apparatuses for business use, and ink-jet recording apparatuses are widely used as image forming apparatuses for general consumers. Such ink-jet recording apparatuses are quiet and can implement high speed recording because the ink-jet recording apparatuses employ non-contact method of printing to recording media. Moreover, the ink-jet recording apparatuses have advantages of high density recording, easy color printing, and the like.
A so-called electrophotographic type image forming apparatus, such as a copier and a laser printer, includes a latent image bearing body, a development unit, transfer means, and a fixation unit. The latent image bearing body bears a latent image. The development unit applies developer to the latent image bearing body to make the latent image visible as a developer image. The transfer means transfers the developer image formed by the development unit to a recording material conveyed in a predetermined direction. The fixation unit fixes the developer image to the recording material by heating and pressing the recording material having the developer image transferred by the transfer means under predetermined fixation process conditions.
The ink-jet recording apparatus generally includes a carriage on which a recording head and an ink tank are mounted, conveying means which conveys recording paper, and control means which controls these components. The ink-jet recording apparatus performs recording on the recording paper in such a manner that the carriage serially scans the recording paper in a direction (a main scanning direction) orthogonal to a conveying direction (a secondary scanning direction) with ink droplets being ejected from a plurality of outlets of the recording head while the recording paper is intermittently conveyed by a distance equal to recording width when the recording is not performed.
In such an image forming apparatus, heretofore, for example, the size and the type (hereafter, referred also to as paper type) of recording materials are set by a user through an operation panel provided for the body of the image forming apparatus. The aforementioned electrophotographic type image forming apparatus, for example, makes a control to change, according to such settings, development conditions, transfer conditions, or the fixation process conditions (for example, fixation temperature and conveying speed of recording materials passing through the fixation unit) or image processing and the like. Alternatively, the user sets a paper type from a host computer at printing, and the image forming apparatus thus makes the control to change the development, transfer, or fixation process conditions or the image processing according to the specified paper type.
The ink-jet type image forming apparatus controls amounts of ink discharged and performs color conversion processing according to the paper type and the like. Alternatively, the user sets a paper type through a host computer connected to the image forming apparatus at printing, and the image forming apparatus performs the above control and processing according to the specified paper type.
However, the user may forget to perform the aforementioned setting of the paper type, make a mistake in the setting, or mix a plurality of paper types. Accordingly, in the image forming apparatuses, especially in the image forming apparatuses for business use, automatic identification of the paper type has been increasingly implemented.
For example, as proposed in the Japanese Patent Application Laid-open Nos. 2002-182518 and 2003-302885, some of the image forming apparatuses identify the type of a recording material by a method of capturing an image of the surface of the recording material with a CMOS sensor to detect surface smoothness of the recording material, and variably control the development, transfer, or fixation conditions. Moreover, another apparatus has been proposed, in which a light emitting source is provided at a position opposite to the sensor which identifies the recording material, and transmitted light is detected in the identification of the recording material using transmitted light. The image forming apparatus has made a control using such a method of identifying the recording material so that the identification would be performed every time a recording material is fed (control as all the recording materials are to be identified) , or made another control so that the identification would be performed only for the first sheet of a print job and is not performed for the subsequent sheets.
However, the aforementioned conventional image forming apparatuses have the following problems. This recording material identification has a tendency to increase measurement time for an improvement in accuracy of the identification. It is necessary to identify various sheets existing on the market. However, if it is configured that all the recording materials are identified, every identification operation takes time, and the productivity is lowered. Moreover, in the case where the identification is performed only on the first sheet of each job and the subsequent sheets are processed using the identification result of the first sheet for control as described above, if the identification of the first sheet is wrong, all the subsequent sheets are subjected to control based on the wrong identification result.